Re: [PATCH 3/4] perf lock contention: Add --output option

From: Ian Rogers
Date: Fri Jun 30 2023 - 12:14:12 EST


On Wed, Jun 28, 2023 at 1:01 PM Namhyung Kim <namhyung@xxxxxxxxxx> wrote:
>
> To avoid formatting failures for example in CSV output due to debug
> messages, add --output option to put the result in a file.
> Unfortunately the short -o option was taken by the --owner already.
>
> $ sudo ./perf lock con -ab --output lock-out.txt -v sleep 1
> Looking at the vmlinux_path (8 entries long)
> symsrc__init: cannot get elf header.
> Using /proc/kcore for kernel data
> Using /proc/kallsyms for symbols
>
> $ head lock-out.txt
> contended total wait max wait avg wait type caller
>
> 3 76.79 us 26.89 us 25.60 us rwlock:R ep_poll_callback+0x2d
> 0xffffffff9a23f4b5 _raw_read_lock_irqsave+0x45
> 0xffffffff99bbd4dd ep_poll_callback+0x2d
> 0xffffffff999029f3 __wake_up_common+0x73
> 0xffffffff99902b82 __wake_up_common_lock+0x82
> 0xffffffff99fa5b1c sock_def_readable+0x3c
> 0xffffffff9a11521d unix_stream_sendmsg+0x18d
> 0xffffffff99f9fc9c sock_sendmsg+0x5c
>
> Suggested-by: Ian Rogers <irogers@xxxxxxxxxx>
> Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>

Making some of my previous suggestions mute :-)

Acked-by: Ian Rogers <irogers@xxxxxxxxxx>

Thanks,
Ian
> ---
> tools/perf/Documentation/perf-lock.txt | 3 +
> tools/perf/builtin-lock.c | 140 +++++++++++++++----------
> 2 files changed, 85 insertions(+), 58 deletions(-)
>
> diff --git a/tools/perf/Documentation/perf-lock.txt b/tools/perf/Documentation/perf-lock.txt
> index d1efcbe7a470..30eea576721f 100644
> --- a/tools/perf/Documentation/perf-lock.txt
> +++ b/tools/perf/Documentation/perf-lock.txt
> @@ -36,6 +36,9 @@ COMMON OPTIONS
> --input=<file>::
> Input file name. (default: perf.data unless stdin is a fifo)
>
> +--output=<file>::
> + Output file name for perf lock contention and report.
> +
> -v::
> --verbose::
> Be more verbose (show symbol address, etc).
> diff --git a/tools/perf/builtin-lock.c b/tools/perf/builtin-lock.c
> index 98b0c0b1b307..c15386cb1033 100644
> --- a/tools/perf/builtin-lock.c
> +++ b/tools/perf/builtin-lock.c
> @@ -27,6 +27,7 @@
> #include "util/map.h"
> #include "util/util.h"
>
> +#include <stdio.h>
> #include <sys/types.h>
> #include <sys/prctl.h>
> #include <semaphore.h>
> @@ -65,6 +66,8 @@ static int max_stack_depth = CONTENTION_STACK_DEPTH;
> static int stack_skip = CONTENTION_STACK_SKIP;
> static int print_nr_entries = INT_MAX / 2;
> static LIST_HEAD(callstack_filters);
> +static const char *output_name = NULL;
> +static FILE *lock_output;
>
> struct callstack_filter {
> struct list_head list;
> @@ -227,7 +230,7 @@ static void lock_stat_key_print_time(unsigned long long nsec, int len)
>
> /* for CSV output */
> if (len == 0) {
> - pr_info("%llu", nsec);
> + fprintf(lock_output, "%llu", nsec);
> return;
> }
>
> @@ -235,18 +238,18 @@ static void lock_stat_key_print_time(unsigned long long nsec, int len)
> if (nsec < table[i].base)
> continue;
>
> - pr_info("%*.2f %s", len - 3, nsec / table[i].base, table[i].unit);
> + fprintf(lock_output, "%*.2f %s", len - 3, nsec / table[i].base, table[i].unit);
> return;
> }
>
> - pr_info("%*llu %s", len - 3, nsec, "ns");
> + fprintf(lock_output, "%*llu %s", len - 3, nsec, "ns");
> }
>
> #define PRINT_KEY(member) \
> static void lock_stat_key_print_ ## member(struct lock_key *key, \
> struct lock_stat *ls) \
> { \
> - pr_info("%*llu", key->len, (unsigned long long)ls->member); \
> + fprintf(lock_output, "%*llu", key->len, (unsigned long long)ls->member);\
> }
>
> #define PRINT_TIME(member) \
> @@ -1335,12 +1338,12 @@ static void print_bad_events(int bad, int total)
> if (quiet || total == 0 || (broken == 0 && verbose <= 0))
> return;
>
> - pr_info("\n=== output for debug ===\n\n");
> - pr_info("bad: %d, total: %d\n", bad, total);
> - pr_info("bad rate: %.2f %%\n", (double)bad / (double)total * 100);
> - pr_info("histogram of events caused bad sequence\n");
> + fprintf(lock_output, "\n=== output for debug ===\n\n");
> + fprintf(lock_output, "bad: %d, total: %d\n", bad, total);
> + fprintf(lock_output, "bad rate: %.2f %%\n", (double)bad / (double)total * 100);
> + fprintf(lock_output, "histogram of events caused bad sequence\n");
> for (i = 0; i < BROKEN_MAX; i++)
> - pr_info(" %10s: %d\n", name[i], bad_hist[i]);
> + fprintf(lock_output, " %10s: %d\n", name[i], bad_hist[i]);
> }
>
> /* TODO: various way to print, coloring, nano or milli sec */
> @@ -1352,10 +1355,10 @@ static void print_result(void)
> int bad, total, printed;
>
> if (!quiet) {
> - pr_info("%20s ", "Name");
> + fprintf(lock_output, "%20s ", "Name");
> list_for_each_entry(key, &lock_keys, list)
> - pr_info("%*s ", key->len, key->header);
> - pr_info("\n\n");
> + fprintf(lock_output, "%*s ", key->len, key->header);
> + fprintf(lock_output, "\n\n");
> }
>
> bad = total = printed = 0;
> @@ -1380,7 +1383,7 @@ static void print_result(void)
> name = thread__comm_str(t);
> }
>
> - pr_info("%20s ", name);
> + fprintf(lock_output, "%20s ", name);
> } else {
> strncpy(cut_name, st->name, 16);
> cut_name[16] = '.';
> @@ -1388,14 +1391,14 @@ static void print_result(void)
> cut_name[18] = '.';
> cut_name[19] = '\0';
> /* cut off name for saving output style */
> - pr_info("%20s ", cut_name);
> + fprintf(lock_output, "%20s ", cut_name);
> }
>
> list_for_each_entry(key, &lock_keys, list) {
> key->print(key, st);
> - pr_info(" ");
> + fprintf(lock_output, " ");
> }
> - pr_info("\n");
> + fprintf(lock_output, "\n");
>
> if (++printed >= print_nr_entries)
> break;
> @@ -1412,13 +1415,13 @@ static void dump_threads(void)
> struct rb_node *node;
> struct thread *t;
>
> - pr_info("%10s: comm\n", "Thread ID");
> + fprintf(lock_output, "%10s: comm\n", "Thread ID");
>
> node = rb_first(&thread_stats);
> while (node) {
> st = container_of(node, struct thread_stat, rb);
> t = perf_session__findnew(session, st->tid);
> - pr_info("%10d: %s\n", st->tid, thread__comm_str(t));
> + fprintf(lock_output, "%10d: %s\n", st->tid, thread__comm_str(t));
> node = rb_next(node);
> thread__put(t);
> }
> @@ -1444,7 +1447,7 @@ static void dump_map(void)
> unsigned int i;
> struct lock_stat *st;
>
> - pr_info("Address of instance: name of class\n");
> + fprintf(lock_output, "Address of instance: name of class\n");
> for (i = 0; i < LOCKHASH_SIZE; i++) {
> hlist_for_each_entry(st, &lockhash_table[i], hash_entry) {
> insert_to_result(st, compare_maps);
> @@ -1452,7 +1455,7 @@ static void dump_map(void)
> }
>
> while ((st = pop_from_result()))
> - pr_info(" %#llx: %s\n", (unsigned long long)st->addr, st->name);
> + fprintf(lock_output, " %#llx: %s\n", (unsigned long long)st->addr, st->name);
> }
>
> static int dump_info(void)
> @@ -1637,18 +1640,18 @@ static void print_header_stdio(void)
> struct lock_key *key;
>
> list_for_each_entry(key, &lock_keys, list)
> - pr_info("%*s ", key->len, key->header);
> + fprintf(lock_output, "%*s ", key->len, key->header);
>
> switch (aggr_mode) {
> case LOCK_AGGR_TASK:
> - pr_info(" %10s %s\n\n", "pid",
> + fprintf(lock_output, " %10s %s\n\n", "pid",
> show_lock_owner ? "owner" : "comm");
> break;
> case LOCK_AGGR_CALLER:
> - pr_info(" %10s %s\n\n", "type", "caller");
> + fprintf(lock_output, " %10s %s\n\n", "type", "caller");
> break;
> case LOCK_AGGR_ADDR:
> - pr_info(" %16s %s\n\n", "address", "symbol");
> + fprintf(lock_output, " %16s %s\n\n", "address", "symbol");
> break;
> default:
> break;
> @@ -1659,23 +1662,23 @@ static void print_header_csv(const char *sep)
> {
> struct lock_key *key;
>
> - pr_info("# output: ");
> + fprintf(lock_output, "# output: ");
> list_for_each_entry(key, &lock_keys, list)
> - pr_info("%s%s ", key->header, sep);
> + fprintf(lock_output, "%s%s ", key->header, sep);
>
> switch (aggr_mode) {
> case LOCK_AGGR_TASK:
> - pr_info("%s%s %s\n", "pid", sep,
> + fprintf(lock_output, "%s%s %s\n", "pid", sep,
> show_lock_owner ? "owner" : "comm");
> break;
> case LOCK_AGGR_CALLER:
> - pr_info("%s%s %s", "type", sep, "caller");
> + fprintf(lock_output, "%s%s %s", "type", sep, "caller");
> if (verbose > 0)
> - pr_info("%s %s", sep, "stacktrace");
> - pr_info("\n");
> + fprintf(lock_output, "%s %s", sep, "stacktrace");
> + fprintf(lock_output, "\n");
> break;
> case LOCK_AGGR_ADDR:
> - pr_info("%s%s %s%s %s\n", "address", sep, "symbol", sep, "type");
> + fprintf(lock_output, "%s%s %s%s %s\n", "address", sep, "symbol", sep, "type");
> break;
> default:
> break;
> @@ -1700,21 +1703,21 @@ static void print_lock_stat_stdio(struct lock_contention *con, struct lock_stat
>
> list_for_each_entry(key, &lock_keys, list) {
> key->print(key, st);
> - pr_info(" ");
> + fprintf(lock_output, " ");
> }
>
> switch (aggr_mode) {
> case LOCK_AGGR_CALLER:
> - pr_info(" %10s %s\n", get_type_str(st->flags), st->name);
> + fprintf(lock_output, " %10s %s\n", get_type_str(st->flags), st->name);
> break;
> case LOCK_AGGR_TASK:
> pid = st->addr;
> t = perf_session__findnew(session, pid);
> - pr_info(" %10d %s\n",
> + fprintf(lock_output, " %10d %s\n",
> pid, pid == -1 ? "Unknown" : thread__comm_str(t));
> break;
> case LOCK_AGGR_ADDR:
> - pr_info(" %016llx %s (%s)\n", (unsigned long long)st->addr,
> + fprintf(lock_output, " %016llx %s (%s)\n", (unsigned long long)st->addr,
> st->name, get_type_name(st->flags));
> break;
> default:
> @@ -1734,7 +1737,7 @@ static void print_lock_stat_stdio(struct lock_contention *con, struct lock_stat
> ip = st->callstack[i];
> sym = machine__find_kernel_symbol(con->machine, ip, &kmap);
> get_symbol_name_offset(kmap, sym, ip, buf, sizeof(buf));
> - pr_info("\t\t\t%#lx %s\n", (unsigned long)ip, buf);
> + fprintf(lock_output, "\t\t\t%#lx %s\n", (unsigned long)ip, buf);
> }
> }
> }
> @@ -1748,22 +1751,23 @@ static void print_lock_stat_csv(struct lock_contention *con, struct lock_stat *s
>
> list_for_each_entry(key, &lock_keys, list) {
> key->print(key, st);
> - pr_info("%s ", sep);
> + fprintf(lock_output, "%s ", sep);
> }
>
> switch (aggr_mode) {
> case LOCK_AGGR_CALLER:
> - pr_info("%s%s %s", get_type_str(st->flags), sep, st->name);
> + fprintf(lock_output, "%s%s %s", get_type_str(st->flags), sep, st->name);
> if (verbose <= 0)
> - pr_info("\n");
> + fprintf(lock_output, "\n");
> break;
> case LOCK_AGGR_TASK:
> pid = st->addr;
> t = perf_session__findnew(session, pid);
> - pr_info("%d%s %s\n", pid, sep, pid == -1 ? "Unknown" : thread__comm_str(t));
> + fprintf(lock_output, "%d%s %s\n", pid, sep,
> + pid == -1 ? "Unknown" : thread__comm_str(t));
> break;
> case LOCK_AGGR_ADDR:
> - pr_info("%llx%s %s%s %s\n", (unsigned long long)st->addr, sep,
> + fprintf(lock_output, "%llx%s %s%s %s\n", (unsigned long long)st->addr, sep,
> st->name, sep, get_type_name(st->flags));
> break;
> default:
> @@ -1783,9 +1787,9 @@ static void print_lock_stat_csv(struct lock_contention *con, struct lock_stat *s
> ip = st->callstack[i];
> sym = machine__find_kernel_symbol(con->machine, ip, &kmap);
> get_symbol_name_offset(kmap, sym, ip, buf, sizeof(buf));
> - pr_info("%s %#lx %s", i ? ":" : sep, (unsigned long) ip, buf);
> + fprintf(lock_output, "%s %#lx %s", i ? ":" : sep, (unsigned long) ip, buf);
> }
> - pr_info("\n");
> + fprintf(lock_output, "\n");
> }
> }
>
> @@ -1809,15 +1813,15 @@ static void print_footer_stdio(int total, int bad, struct lock_contention_fails
> return;
>
> total += broken;
> - pr_info("\n=== output for debug ===\n\n");
> - pr_info("bad: %d, total: %d\n", broken, total);
> - pr_info("bad rate: %.2f %%\n", (double)broken / (double)total * 100);
> + fprintf(lock_output, "\n=== output for debug ===\n\n");
> + fprintf(lock_output, "bad: %d, total: %d\n", broken, total);
> + fprintf(lock_output, "bad rate: %.2f %%\n", 100.0 * broken / total);
>
> - pr_info("histogram of failure reasons\n");
> - pr_info(" %10s: %d\n", "task", fails->task);
> - pr_info(" %10s: %d\n", "stack", fails->stack);
> - pr_info(" %10s: %d\n", "time", fails->time);
> - pr_info(" %10s: %d\n", "data", fails->data);
> + fprintf(lock_output, "histogram of failure reasons\n");
> + fprintf(lock_output, " %10s: %d\n", "task", fails->task);
> + fprintf(lock_output, " %10s: %d\n", "stack", fails->stack);
> + fprintf(lock_output, " %10s: %d\n", "time", fails->time);
> + fprintf(lock_output, " %10s: %d\n", "data", fails->data);
> }
>
> static void print_footer_csv(int total, int bad, struct lock_contention_fails *fails,
> @@ -1831,21 +1835,21 @@ static void print_footer_csv(int total, int bad, struct lock_contention_fails *f
> return;
>
> total += bad;
> - pr_info("# debug: total=%d%s bad=%d", total, sep, bad);
> + fprintf(lock_output, "# debug: total=%d%s bad=%d", total, sep, bad);
>
> if (use_bpf) {
> - pr_info("%s bad_%s=%d", sep, "task", fails->task);
> - pr_info("%s bad_%s=%d", sep, "stack", fails->stack);
> - pr_info("%s bad_%s=%d", sep, "time", fails->time);
> - pr_info("%s bad_%s=%d", sep, "data", fails->data);
> + fprintf(lock_output, "%s bad_%s=%d", sep, "task", fails->task);
> + fprintf(lock_output, "%s bad_%s=%d", sep, "stack", fails->stack);
> + fprintf(lock_output, "%s bad_%s=%d", sep, "time", fails->time);
> + fprintf(lock_output, "%s bad_%s=%d", sep, "data", fails->data);
> } else {
> int i;
> const char *name[4] = { "acquire", "acquired", "contended", "release" };
>
> for (i = 0; i < BROKEN_MAX; i++)
> - pr_info("%s bad_%s=%d", sep, name[i], bad_hist[i]);
> + fprintf(lock_output, "%s bad_%s=%d", sep, name[i], bad_hist[i]);
> }
> - pr_info("\n");
> + fprintf(lock_output, "\n");
> }
>
> static void print_footer(int total, int bad, struct lock_contention_fails *fails)
> @@ -2427,10 +2431,29 @@ static int parse_call_stack(const struct option *opt __maybe_unused, const char
> return ret;
> }
>
> +static int parse_output(const struct option *opt __maybe_unused, const char *str,
> + int unset __maybe_unused)
> +{
> + const char **name = (const char **)opt->value;
> +
> + if (str == NULL)
> + return -1;
> +
> + lock_output = fopen(str, "w");
> + if (lock_output == NULL) {
> + pr_err("Cannot open %s\n", str);
> + return -1;
> + }
> +
> + *name = str;
> + return 0;
> +}
> +
> int cmd_lock(int argc, const char **argv)
> {
> const struct option lock_options[] = {
> OPT_STRING('i', "input", &input_name, "file", "input file name"),
> + OPT_CALLBACK(0, "output", &output_name, "file", "output file name", parse_output),
> OPT_INCR('v', "verbose", &verbose, "be more verbose (show symbol address, etc)"),
> OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace, "dump raw trace in ASCII"),
> OPT_BOOLEAN('f', "force", &force, "don't complain, do it"),
> @@ -2530,6 +2553,7 @@ int cmd_lock(int argc, const char **argv)
> for (i = 0; i < LOCKHASH_SIZE; i++)
> INIT_HLIST_HEAD(lockhash_table + i);
>
> + lock_output = stderr;
> argc = parse_options_subcommand(argc, argv, lock_options, lock_subcommands,
> lock_usage, PARSE_OPT_STOP_AT_NON_OPTION);
> if (!argc)
> --
> 2.41.0.255.g8b1d071c50-goog
>